diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 07dcbba019ade..0118b72962de3 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -3777,7 +3777,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         let tcx = self.infcx.tcx;
         if let Some(Terminator { kind: TerminatorKind::Call { call_source, fn_span, .. }, .. }) =
             &self.body[loan.reserve_location.block].terminator
-            && let Some((method_did, method_args)) = rustc_middle::util::find_self_call(
+            && let Some((method_did, method_args)) = mir::find_self_call(
                 tcx,
                 self.body,
                 loan.assigned_place.local,
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index bd6f77156ca99..5fe8eef346008 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -17,7 +17,7 @@ use rustc_middle::mir::tcx::PlaceTy;
 use rustc_middle::mir::{
     AggregateKind, CallSource, ConstOperand, ConstraintCategory, FakeReadCause, Local, LocalInfo,
     LocalKind, Location, Operand, Place, PlaceRef, ProjectionElem, Rvalue, Statement,
-    StatementKind, Terminator, TerminatorKind,
+    StatementKind, Terminator, TerminatorKind, find_self_call,
 };
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, Ty, TyCtxt};
@@ -1016,12 +1016,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             kind: TerminatorKind::Call { fn_span, call_source, .. }, ..
         }) = &self.body[location.block].terminator
         {
-            let Some((method_did, method_args)) = rustc_middle::util::find_self_call(
-                self.infcx.tcx,
-                self.body,
-                target_temp,
-                location.block,
-            ) else {
+            let Some((method_did, method_args)) =
+                find_self_call(self.infcx.tcx, self.body, target_temp, location.block)
+            else {
                 return normal_ret;
             };
 
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index 65d586124b33a..6ef73debadd50 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -76,6 +76,7 @@ pub mod sync;
 pub mod tagged_ptr;
 pub mod temp_dir;
 pub mod thinvec;
+pub mod thousands;
 pub mod transitive_relation;
 pub mod unhash;
 pub mod unord;
diff --git a/compiler/rustc_data_structures/src/thousands/mod.rs b/compiler/rustc_data_structures/src/thousands/mod.rs
new file mode 100644
index 0000000000000..e7ab7ec2932df
--- /dev/null
+++ b/compiler/rustc_data_structures/src/thousands/mod.rs
@@ -0,0 +1,16 @@
+//! This is an extremely bare-bones alternative to the `thousands` crate on
+//! crates.io, for printing large numbers in a readable fashion.
+
+#[cfg(test)]
+mod tests;
+
+// Converts the number to a string, with underscores as the thousands separator.
+pub fn format_with_underscores(n: usize) -> String {
+    let mut s = n.to_string();
+    let mut i = s.len();
+    while i > 3 {
+        i -= 3;
+        s.insert(i, '_');
+    }
+    s
+}
diff --git a/compiler/rustc_data_structures/src/thousands/tests.rs b/compiler/rustc_data_structures/src/thousands/tests.rs
new file mode 100644
index 0000000000000..906605d9a935d
--- /dev/null
+++ b/compiler/rustc_data_structures/src/thousands/tests.rs
@@ -0,0 +1,14 @@
+use super::*;
+
+#[test]
+fn test_format_with_underscores() {
+    assert_eq!("0", format_with_underscores(0));
+    assert_eq!("1", format_with_underscores(1));
+    assert_eq!("99", format_with_underscores(99));
+    assert_eq!("345", format_with_underscores(345));
+    assert_eq!("1_000", format_with_underscores(1_000));
+    assert_eq!("12_001", format_with_underscores(12_001));
+    assert_eq!("999_999", format_with_underscores(999_999));
+    assert_eq!("1_000_000", format_with_underscores(1_000_000));
+    assert_eq!("12_345_678", format_with_underscores(12_345_678));
+}
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 904409dd777ea..43372154b2ce4 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -9,6 +9,7 @@ use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_data_structures::memmap::{Mmap, MmapMut};
 use rustc_data_structures::sync::{Lrc, join, par_for_each_in};
 use rustc_data_structures::temp_dir::MaybeTempDir;
+use rustc_data_structures::thousands::format_with_underscores;
 use rustc_feature::Features;
 use rustc_hir as hir;
 use rustc_hir::def_id::{CRATE_DEF_ID, CRATE_DEF_INDEX, LOCAL_CRATE, LocalDefId, LocalDefIdSet};
@@ -22,7 +23,6 @@ use rustc_middle::traits::specialization_graph;
 use rustc_middle::ty::codec::TyEncoder;
 use rustc_middle::ty::fast_reject::{self, TreatParams};
 use rustc_middle::ty::{AssocItemContainer, SymbolName};
-use rustc_middle::util::common::to_readable_str;
 use rustc_middle::{bug, span_bug};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder, opaque};
 use rustc_session::config::{CrateType, OptLevel};
@@ -782,7 +782,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     "{} {:<23}{:>10} ({:4.1}%)",
                     prefix,
                     label,
-                    to_readable_str(size),
+                    format_with_underscores(size),
                     perc(size)
                 );
             }
@@ -791,7 +791,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 "{} {:<23}{:>10} (of which {:.1}% are zero bytes)",
                 prefix,
                 "Total",
-                to_readable_str(total_bytes),
+                format_with_underscores(total_bytes),
                 perc(zero_bytes)
             );
             eprintln!("{prefix}");
diff --git a/compiler/rustc_middle/src/macros.rs b/compiler/rustc_middle/src/macros.rs
index 39816c17b985f..b3064d8fe25cb 100644
--- a/compiler/rustc_middle/src/macros.rs
+++ b/compiler/rustc_middle/src/macros.rs
@@ -4,8 +4,8 @@
 ///
 /// If you have a span available, you should use [`span_bug`] instead.
 ///
-/// If the bug should only be emitted when compilation didn't fail, [`DiagCtxtHandle::span_delayed_bug`]
-/// may be useful.
+/// If the bug should only be emitted when compilation didn't fail,
+/// [`DiagCtxtHandle::span_delayed_bug`] may be useful.
 ///
 /// [`DiagCtxtHandle::span_delayed_bug`]: rustc_errors::DiagCtxtHandle::span_delayed_bug
 /// [`span_bug`]: crate::span_bug
@@ -14,14 +14,8 @@ macro_rules! bug {
     () => (
         $crate::bug!("impossible case reached")
     );
-    ($msg:expr) => (
-        $crate::util::bug::bug_fmt(::std::format_args!($msg))
-    );
-    ($msg:expr,) => (
-        $crate::bug!($msg)
-    );
-    ($fmt:expr, $($arg:tt)+) => (
-        $crate::util::bug::bug_fmt(::std::format_args!($fmt, $($arg)+))
+    ($($arg:tt)+) => (
+        $crate::util::bug::bug_fmt(::std::format_args!($($arg)+))
     );
 }
 
@@ -30,20 +24,14 @@ macro_rules! bug {
 /// at the code the compiler was compiling when it ICEd. This is the preferred way to trigger
 /// ICEs.
 ///
-/// If the bug should only be emitted when compilation didn't fail, [`DiagCtxtHandle::span_delayed_bug`]
-/// may be useful.
+/// If the bug should only be emitted when compilation didn't fail,
+/// [`DiagCtxtHandle::span_delayed_bug`] may be useful.
 ///
 /// [`DiagCtxtHandle::span_delayed_bug`]: rustc_errors::DiagCtxtHandle::span_delayed_bug
 #[macro_export]
 macro_rules! span_bug {
-    ($span:expr, $msg:expr) => (
-        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($msg))
-    );
-    ($span:expr, $msg:expr,) => (
-        $crate::span_bug!($span, $msg)
-    );
-    ($span:expr, $fmt:expr, $($arg:tt)+) => (
-        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($fmt, $($arg)+))
+    ($span:expr, $($arg:tt)+) => (
+        $crate::util::bug::span_bug_fmt($span, ::std::format_args!($($arg)+))
     );
 }
 
@@ -53,7 +41,6 @@ macro_rules! span_bug {
 // When possible, use one of these (relatively) convenient macros to write
 // the impls for you.
 
-#[macro_export]
 macro_rules! TrivialLiftImpls {
     ($($ty:ty),+ $(,)?) => {
         $(
@@ -69,7 +56,6 @@ macro_rules! TrivialLiftImpls {
 
 /// Used for types that are `Copy` and which **do not care about arena
 /// allocated data** (i.e., don't need to be folded).
-#[macro_export]
 macro_rules! TrivialTypeTraversalImpls {
     ($($ty:ty),+ $(,)?) => {
         $(
@@ -104,7 +90,6 @@ macro_rules! TrivialTypeTraversalImpls {
     };
 }
 
-#[macro_export]
 macro_rules! TrivialTypeTraversalAndLiftImpls {
     ($($t:tt)*) => {
         TrivialTypeTraversalImpls! { $($t)* }
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 0f3fca434eecf..cfb78e5dddff6 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -27,7 +27,7 @@ use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisit
 use rustc_serialize::{Decodable, Encodable};
 use rustc_span::source_map::Spanned;
 use rustc_span::{DUMMY_SP, Span, Symbol};
-use tracing::trace;
+use tracing::{debug, trace};
 
 pub use self::query::*;
 use self::visit::TyContext;
@@ -1796,6 +1796,47 @@ impl DefLocation {
     }
 }
 
+/// Checks if the specified `local` is used as the `self` parameter of a method call
+/// in the provided `BasicBlock`. If it is, then the `DefId` of the called method is
+/// returned.
+pub fn find_self_call<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    body: &Body<'tcx>,
+    local: Local,
+    block: BasicBlock,
+) -> Option<(DefId, GenericArgsRef<'tcx>)> {
+    debug!("find_self_call(local={:?}): terminator={:?}", local, body[block].terminator);
+    if let Some(Terminator { kind: TerminatorKind::Call { func, args, .. }, .. }) =
+        &body[block].terminator
+        && let Operand::Constant(box ConstOperand { const_, .. }) = func
+        && let ty::FnDef(def_id, fn_args) = *const_.ty().kind()
+        && let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
+            tcx.opt_associated_item(def_id)
+        && let [Spanned { node: Operand::Move(self_place) | Operand::Copy(self_place), .. }, ..] =
+            **args
+    {
+        if self_place.as_local() == Some(local) {
+            return Some((def_id, fn_args));
+        }
+
+        // Handle the case where `self_place` gets reborrowed.
+        // This happens when the receiver is `&T`.
+        for stmt in &body[block].statements {
+            if let StatementKind::Assign(box (place, rvalue)) = &stmt.kind
+                && let Some(reborrow_local) = place.as_local()
+                && self_place.as_local() == Some(reborrow_local)
+                && let Rvalue::Ref(_, _, deref_place) = rvalue
+                && let PlaceRef { local: deref_local, projection: [ProjectionElem::Deref] } =
+                    deref_place.as_ref()
+                && deref_local == local
+            {
+                return Some((def_id, fn_args));
+            }
+        }
+    }
+    None
+}
+
 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.
 #[cfg(target_pointer_width = "64")]
 mod size_asserts {
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 8a9110f842a94..28a6eba75aa56 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -428,7 +428,7 @@ pub enum IsConstable {
     Ctor,
 }
 
-crate::TrivialTypeTraversalAndLiftImpls! {
+TrivialTypeTraversalAndLiftImpls! {
     IsConstable,
 }
 
diff --git a/compiler/rustc_middle/src/util/bug.rs b/compiler/rustc_middle/src/util/bug.rs
index b99336c2c85ba..7dda68b8393a1 100644
--- a/compiler/rustc_middle/src/util/bug.rs
+++ b/compiler/rustc_middle/src/util/bug.rs
@@ -1,4 +1,4 @@
-// These functions are used by macro expansion for bug! and span_bug!
+// These functions are used by macro expansion for `bug!` and `span_bug!`.
 
 use std::fmt;
 use std::panic::{Location, panic_any};
@@ -8,15 +8,15 @@ use rustc_span::Span;
 
 use crate::ty::{TyCtxt, tls};
 
+// This wrapper makes for more compact code at callsites than calling `opt_span_buf_fmt` directly.
 #[cold]
 #[inline(never)]
 #[track_caller]
 pub fn bug_fmt(args: fmt::Arguments<'_>) -> ! {
-    // this wrapper mostly exists so I don't have to write a fully
-    // qualified path of None::<Span> inside the bug!() macro definition
     opt_span_bug_fmt(None::<Span>, args, Location::caller());
 }
 
+// This wrapper makes for more compact code at callsites than calling `opt_span_buf_fmt` directly.
 #[cold]
 #[inline(never)]
 #[track_caller]
diff --git a/compiler/rustc_middle/src/util/common.rs b/compiler/rustc_middle/src/util/common.rs
deleted file mode 100644
index 223b2b3bfe4de..0000000000000
--- a/compiler/rustc_middle/src/util/common.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-#[cfg(test)]
-mod tests;
-
-pub fn to_readable_str(mut val: usize) -> String {
-    let mut groups = vec![];
-    loop {
-        let group = val % 1000;
-
-        val /= 1000;
-
-        if val == 0 {
-            groups.push(group.to_string());
-            break;
-        } else {
-            groups.push(format!("{group:03}"));
-        }
-    }
-
-    groups.reverse();
-
-    groups.join("_")
-}
diff --git a/compiler/rustc_middle/src/util/common/tests.rs b/compiler/rustc_middle/src/util/common/tests.rs
deleted file mode 100644
index 9a9fb203c625e..0000000000000
--- a/compiler/rustc_middle/src/util/common/tests.rs
+++ /dev/null
@@ -1,14 +0,0 @@
-use super::*;
-
-#[test]
-fn test_to_readable_str() {
-    assert_eq!("0", to_readable_str(0));
-    assert_eq!("1", to_readable_str(1));
-    assert_eq!("99", to_readable_str(99));
-    assert_eq!("999", to_readable_str(999));
-    assert_eq!("1_000", to_readable_str(1_000));
-    assert_eq!("1_001", to_readable_str(1_001));
-    assert_eq!("999_999", to_readable_str(999_999));
-    assert_eq!("1_000_000", to_readable_str(1_000_000));
-    assert_eq!("1_234_567", to_readable_str(1_234_567));
-}
diff --git a/compiler/rustc_middle/src/util/find_self_call.rs b/compiler/rustc_middle/src/util/find_self_call.rs
deleted file mode 100644
index 0fdd352073860..0000000000000
--- a/compiler/rustc_middle/src/util/find_self_call.rs
+++ /dev/null
@@ -1,47 +0,0 @@
-use rustc_span::def_id::DefId;
-use rustc_span::source_map::Spanned;
-use tracing::debug;
-
-use crate::mir::*;
-use crate::ty::{self, GenericArgsRef, TyCtxt};
-
-/// Checks if the specified `local` is used as the `self` parameter of a method call
-/// in the provided `BasicBlock`. If it is, then the `DefId` of the called method is
-/// returned.
-pub fn find_self_call<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    body: &Body<'tcx>,
-    local: Local,
-    block: BasicBlock,
-) -> Option<(DefId, GenericArgsRef<'tcx>)> {
-    debug!("find_self_call(local={:?}): terminator={:?}", local, body[block].terminator);
-    if let Some(Terminator { kind: TerminatorKind::Call { func, args, .. }, .. }) =
-        &body[block].terminator
-        && let Operand::Constant(box ConstOperand { const_, .. }) = func
-        && let ty::FnDef(def_id, fn_args) = *const_.ty().kind()
-        && let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
-            tcx.opt_associated_item(def_id)
-        && let [Spanned { node: Operand::Move(self_place) | Operand::Copy(self_place), .. }, ..] =
-            **args
-    {
-        if self_place.as_local() == Some(local) {
-            return Some((def_id, fn_args));
-        }
-
-        // Handle the case where `self_place` gets reborrowed.
-        // This happens when the receiver is `&T`.
-        for stmt in &body[block].statements {
-            if let StatementKind::Assign(box (place, rvalue)) = &stmt.kind
-                && let Some(reborrow_local) = place.as_local()
-                && self_place.as_local() == Some(reborrow_local)
-                && let Rvalue::Ref(_, _, deref_place) = rvalue
-                && let PlaceRef { local: deref_local, projection: [ProjectionElem::Deref] } =
-                    deref_place.as_ref()
-                && deref_local == local
-            {
-                return Some((def_id, fn_args));
-            }
-        }
-    }
-    None
-}
diff --git a/compiler/rustc_middle/src/util/mod.rs b/compiler/rustc_middle/src/util/mod.rs
index 097a868191c15..8c875007b7fb9 100644
--- a/compiler/rustc_middle/src/util/mod.rs
+++ b/compiler/rustc_middle/src/util/mod.rs
@@ -1,8 +1,4 @@
 pub mod bug;
-pub mod common;
-pub mod find_self_call;
-
-pub use find_self_call::find_self_call;
 
 #[derive(Default, Copy, Clone)]
 pub struct Providers {
diff --git a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
index 7968b666dff2f..3affe4abbfad8 100644
--- a/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
+++ b/compiler/rustc_mir_transform/src/check_const_item_mutation.rs
@@ -133,7 +133,7 @@ impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
                 // the `self` parameter of a method call (as the terminator of our current
                 // BasicBlock). If so, we emit a more specific lint.
                 let method_did = self.target_local.and_then(|target_local| {
-                    rustc_middle::util::find_self_call(self.tcx, self.body, target_local, loc.block)
+                    find_self_call(self.tcx, self.body, target_local, loc.block)
                 });
                 let lint_loc =
                     if method_did.is_some() { self.body.terminator_loc(loc.block) } else { loc };
diff --git a/compiler/rustc_passes/src/input_stats.rs b/compiler/rustc_passes/src/input_stats.rs
index 75b62a40ff9f0..6d9c70177a4d4 100644
--- a/compiler/rustc_passes/src/input_stats.rs
+++ b/compiler/rustc_passes/src/input_stats.rs
@@ -5,10 +5,10 @@
 use rustc_ast::visit::BoundKind;
 use rustc_ast::{self as ast, NodeId, visit as ast_visit};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::thousands::format_with_underscores;
 use rustc_hir::{self as hir, AmbigArg, HirId, intravisit as hir_visit};
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::TyCtxt;
-use rustc_middle::util::common::to_readable_str;
 use rustc_span::Span;
 use rustc_span::def_id::LocalDefId;
 
@@ -144,10 +144,10 @@ impl<'k> StatCollector<'k> {
                 "{} {:<18}{:>10} ({:4.1}%){:>14}{:>14}",
                 prefix,
                 label,
-                to_readable_str(size),
+                format_with_underscores(size),
                 percent(size, total_size),
-                to_readable_str(node.stats.count),
-                to_readable_str(node.stats.size)
+                format_with_underscores(node.stats.count),
+                format_with_underscores(node.stats.size)
             );
             if !node.subnodes.is_empty() {
                 // We will soon sort, so the initial order does not matter.
@@ -163,9 +163,9 @@ impl<'k> StatCollector<'k> {
                         "{} - {:<18}{:>10} ({:4.1}%){:>14}",
                         prefix,
                         label,
-                        to_readable_str(size),
+                        format_with_underscores(size),
                         percent(size, total_size),
-                        to_readable_str(subnode.count),
+                        format_with_underscores(subnode.count),
                     );
                 }
             }
@@ -175,8 +175,8 @@ impl<'k> StatCollector<'k> {
             "{} {:<18}{:>10}        {:>14}",
             prefix,
             "Total",
-            to_readable_str(total_size),
-            to_readable_str(total_count),
+            format_with_underscores(total_size),
+            format_with_underscores(total_count),
         );
         eprintln!("{prefix}");
     }